Fixed issue where onQuit() was not being called

Added missing @EventHandler to before onQuit() to ensure bukkit calls it on leave, and to ensure reset on disconnect works.
Moved config handling to KillStreakManager and created the method shouldResetOnDisconnect()
Removed useless comments from file
Exchanged Metrics for MetricsLite
Changed comments for formatted JavaDoc comments.

Added proper JavaDoc formatted comments, replacing the old ones
Added shouldResetOnDisconnect method to allow for configuration independence
Removed plugin reference from KillStreakEventListener

Changed Metrics constructor to MetricsLite